There are known cyber attacks or the like that use a computer system, the Internet or the like to illegally intrude into a target computer or a network to perform fraud, destruction, tampering or the like of data, thereby, causing the target system to malfunction.
A vulnerability scan for checking whether or not a Web site is vulnerable is known as an example of a cyber attack on a Web site on which a Web application (hereinafter, referred to as a Web app) runs. If vulnerability is found on the Web site, a cyber attacker performs fraud, destruction, tampering or the like of the data based on the vulnerability, and makes the Web site malfunction.
There is a known technology (for example, refer to Japanese Laid-open Patent Publication No. 2016-91402) in which each piece of information of an apparatus, a network, and vulnerability is applied to a predetermined algorithm based on graph theory, and a risk evaluation model for defining influence relationships of vulnerability according to an arrangement of each device on the network is created, and thereby, risk corresponding to an actual system situation is evaluated.
There is a known technology (for example, refer to Japanese Laid-open Patent Publication No. 2002-251374) in which a management manager is notified that a sign of abnormality is detected by analyzing a log, and then determines a countermeasure and a countermeasure request destination, causes the countermeasure to be performed in the countermeasure request destination, and thereby, damage due to an attack on a site is minimized.
There is a known technology (for example, refer to International Publication Pamphlet No. WO2012-132296) in which a response message including personal information among response messages corresponding to request messages is resided for a predetermined retention time, if the number of retained response messages exceeds a predetermined number, protection processing is performed, and thereby, information may be not leaked.